STOCKTON - Rail officials took a step back from a plan to send special trains to 49er games 10 days a year in the team's first season in Santa Clara.

The Altamont Corridor Express, which connects Stockton to San Jose on weekdays, already stops within walking distance of Levi's Stadium, the 49ers' soon-to-be home turf. Adding some special trains on the weekend wouldn't be something new for the rail service, which in the past has brought passengers to Raiders and A's games in Oakland.

But the success of those trains depends on marketing help from the professional sports teams, something San Joaquin Regional Rail Commission members wanted to know more about before getting behind a 10-train commitment to the 49ers.

And it hasn't always been enough.

"If they can't put their money where their mouth is, it leaves us holding the bag," said Stacey Mortensen, the rail commission's executive director.

Rail commissioners were considering approving the deal, in concept, at their monthly meeting Friday. But they pushed back a decision by a month to find out what to expect from the 49ers and more details about previous special trains. They also wanted more information about what kind of security would be needed on the train and a better idea about how many other special trains ACE could run if it goes ahead with 10 trains to 49er games.

The ACE train has only 10 special trains available per year, but it can negotiate with Union Pacific to add more. Besides sporting events, those trains have been used to take riders to the Stockton Asparagus Festival, the San Jose Jazz Festival and the Great America amusement park.

Scott Haggerty, a rail commissioner and a member of the Alameda County Board of Supervisors, said he was concerned that the plan for 49ers trains uses up all 10 of the special trains. "It puts all our eggs in one basket."

The idea is to offer train tickets to the game at a discounted price ranging from $12 to $15. At this price, it would take 600 passengers per trip to be successful, according to Thomas Reeves, ACE's public relations manager. With 10,000 season-ticket holders in the San Joaquin Valley and East Bay areas, the 600-passenger target is within reach, he said.

Compared to the cost of gas and parking a driver would incur going to the game, this would be a very competitive price, Reeves said. And it is convenient, he said. "It's within a stone's throw away from our Great America station."

The marketing partnership can make a difference in whether enough people board the special trains, officials said. The rail connection to Oakland A's games was successful during its first two years, ACE's Mortensen said. But support from the team fell off in the third year, and the train's popularity waned, she said.

Kathy Miller, a rail commissioner and a Stockton City Council member, said she didn't want a final agreement to lock ACE into 10 trains if there is inadequate marketing support from the 49ers. "I have no problems going into this if they are willing to meet their end of the bargain and market this like crazy ... and they fill those trains," she said.

Finding fans willing to take the train shouldn't be a problem, Gary Mello said at the meeting. The Pleasanton resident and former Fremont City Council member said he's been telling everyone he knows the trains could be coming. "I think your response to these special trains is going to be overwhelming."

He said ACE could sell out even if it charged twice the discounted price, especially against division rivals, such as the team that knocked the 49ers out of the playoffs one game shy of the Super Bowl.

"Obviously, (with a game against the) Seattle (Seahawks), you will sell out every single car and then some," Mello said.

Contact reporter Zachary K. Johnson at (209) 546-8258 or zjohnson@recordnet.com. Follow him at recordnet.com/johnsonblog and on Twitter @zacharykjohnson.